uart_multiproc_master.a51

Atmel Uart C51程序（主方式）

$INCLUDE   (reg_c51.INC)
TxOK BIT 21H; software flag

org 000h
ljmp begin

org 23h
ljmp serial_IT

;/**
; * FUNCTION_PURPOSE: This file set up uart in mode 3 (9 bits uart) with
; * timer 1 in baud rate generator mode.
; * FUNCTION_INPUTS: P3.2(INT0)
; * FUNCTION_OUTPUTS: void
; */
org 0100h

begin:
	MOV SCON, #0F0h;				  /* uart in mode 3 (9 bit), REN=1 */
   MOV SADDR,#01h;              /* local address */ 
   MOV SADEN,#0FFh;             /* address mask */
	ORL TMOD, #20h;              /* Timer 1 in mode 2 */
	MOV TH1, #0FDh;              /* 9600 Bds at 11.059MHz */
	MOV TL1, #0FDh; 				  /* 9600 Bds at 11.059MHz */
	SETB ES; 						  /* Enable serial interrupt	*/
	SETB EA;						     /* Enable global interrupt */
	SETB TR1; 						  /* Timer 1 run */


loop:
JB       P3.2,$;                /* wait P3_2(INT0)=0 */ 
JNB      P3.2,$;                /* wait P3_2(INT0)=1 */

   SETB     TB8;                /* address mode */ 
   SETB     TxOK;               /* set software flag */ 
   MOV      SBUF,#03h;          /* send slave adress */
   JB       TxOK,$;             /* wait the stop bit transmition */
   CLR      TB8;                /* data mode */
   SETB     TxOK;               /* set software flag */ 
   MOV      SBUF,#55h;          /* send data example */
   JB       TxOK,$;             /* wait the stop bit transmition */

SJMP     loop

;/**
; * FUNCTION_PURPOSE: serial interrupt, 
; * FUNCTION_INPUTS: P3.0(RXD) serial input
; * FUNCTION_OUTPUTS: none
; */
serial_IT:
   JNB      TI,END_Test_TI
   CLR      TI
   CLR      TxOK
END_Test_TI:

   JNB      RI,END_Test_RI;     /* test if it is a reception */
   CLR      RI;                 /* clear reception flag for next reception */
   JNB      RB8,address_mode
   CLR      SM2;                /* go into data mode */
   LJMP END_Test_RB8     
address_mode:
   MOV      A,SBUF;             /* Read receive data */
   SETB     SM2;                /* return into address mode after receive data */
   MOV      P2,A
END_Test_RB8:
END_Test_RI:
   RETI     


end